1. Technical Field
Aspects of this document relate generally to telecommunication systems and techniques for transmitting data across a telecommunication channel.
2. Background Art
Since the introduction of the Global Positioning System (GPS), the benefits provided by GPS are in use by communications and positioning systems to provide extremely accurate timing and positioning information throughout the world. The GPS, GLONASS, and soon to be launched Galileo system, utilize multiple center frequencies for operation. The most common frequency is known as L1 and operates at a center frequency of 1,575.42 MHz. The L1 frequency used by GPS supports two modes of operation: Coarse/Acquisition (C/A) using Binary-Phase Shift Keying (BPSK) over an occupied bandwidth of 1.023 MHz, and precision (P) code in Quadrature Phase Shift Keying (QPSK) over an occupied bandwidth of 10.23 MHz. A second center frequency known as L2 and operates at 1,227.60 MHz and utilizes the P code. Additional codes know as L3 (operating at 1,381.05 MHz), L4 (operating at 1,379.913 MHz) and L5 (operating at 1,176.45 MHz) are being considered or under study for future use.
Communications devices use coaxial connections between the indoor and outdoor electronics for operation at frequencies from 950 MHz to over 2,150 MHz. This well known frequency is known in the art as the Intermediate Frequency (IF). In many cases, the passband of the electronic devices is not at the same frequency as the GPS carrier signal. Since many communications devices may not require L2-L5 GPS frequencies, the L1 frequency, operating at 1,575.42 MHz, is the most prolific frequency used for operation. Thus, a need exists for the ability to combine an unaltered GPS carrier signal with existing communication carrier signals flowing between the outdoor and indoor communications devices.